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Tuesday, September 24, 2019

Brunetti Taxi Drive

Here's a pretty interesting lower gain overdrive. There's a an opamp gain stage with soft clipping going into a JFET stage that pushes a modified BMP tone stack, followed by a BJT output buffer. One of the diodes in the opamp stage is unknown, so socket and experiment. I also took a few liberties from the original using a TL072 instead of a TL071 for layout purposes and using the second opamp to buffer the voltage reference. Should fit nicely in a 1590B. Schematic available on FSB.






5 comments:

  1. Thanks for the layout. Maybe the diode in doubt could be a BAT41 or 1N60, because I believe it is just to have an asymmetric clip. You could provide your email address. I would like to submit a wah project.

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    1. Whatever that diode is, it has a higher forward voltage than the 1N4148s. (1.5v vs .7 and .8v in the circuit) And send via faceboook if you don't mind.

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  2. Thank you for all the great works here. I have built one on this layout but have too shrill tone. Compared to the schematic on FSB, I think R9(22k) between FET-Gate and 10nFCAP is missing. I'll try squeezing 22k into my build.

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  3. As mentioned above, 22k is missing. Second 47n cap at the bottom is connected to ground but it should be b/w 1.5k and 220k resistor, and be connected to 220k and ground (or 4.5v) based on FSB. With the corrections, I verified. Very cool overdrive. Thank you for sharing.

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  4. Me parece que falta um resistor na base do buffer de saída BJT, ligado a referência de tensão 4,5v...

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